Greensboro, North Carolina (CNN) - John Edwards' defense team hammered away at a former campaign aide on Thursday after he was quizzed about his motives and asked whether he made up stories about how Edwards allegedly concealed contributions from campaign donors.

On day four of the trial, Andrew Young, the former aide, said "we lost our perspective" during cross examinations, acknowledging using donations for personal expenses at a California home. Young, testifying in U.S. District Court in Greensboro, North Carolina, said he used the funds in constructing a pool and a theater.